Studies on organic EL devices are flourishing. An active matrix drive is used for controlling the light-emission and non-emission of organic EL devices. Japanese Patent Application Laid-Open No. H08-054836 describes power electrodes, organic EL devices and TFTs to control the light-emission and non-emission of organic EL devices.
Japanese Patent Application Laid-Open No. H08-054836 has an object to decrease the voltage applied to a current-control type light emitting device and reduce power consumption. The problem to be solved so far has been thus to reduce power consumption by decreasing the voltage applied to light emitting devices. On the other hand, the present inventors have paid attention to not raising power source voltage. Not raising power source voltage (not set high) is important with a view of achieving power consumption reduction.
Then, the present inventors have extensively studied and noticed the following fact. That is, for not raising the power source voltage (not setting high), setting as equally as possible the driving voltages of light emitting devices for each color is important.